Waving a magic wand over an injured bone to create a custom, living repair patch sounds like something out of I, Robot. But researchers have created a handheld 3D-printing pen that could someday do just that. It's not magic, it's science.

The BioPen, developed at Australia's University of Wollongong, holds two different "inks:" one made of human cells, the other a protective, UV-activated structural gel. The pen layers the cells inside the protective gel, which hardens under the device's built-in UV light. Instead of the current weeks-long process of harvesting and growing replacement cartilage tissue, the compact, handheld device could enable doctors to "draw" functional material directly on to a damaged bone.

The benefit, as with most 3D-printed organs and body parts, is total customization. Instead of mass-produced orthopedic implants, which don't work exactly like human tissue, a matrix of human cells printed directly onto an injured bone would create actual, functional cartilage. And with the right mix of cells, growth factors, and drugs in the ink wells, doctors could even draw replacement tissue that would grow into functioning nerve or muscle tissue, with the protective scaffold biodegrading as the cells grew and matured.

At the dawn of rapid prototyping, a common predication was that 3D printing would transform…
Read more Read more

All of this, of course, is still far enough out to be more science fiction than fact; this week, the pen was turned over to researchers at St. Vincent's Hospital Melbourne, who will work to optimize the stem cell materials that will make up the living half of the pen's ink. The team estimates that human clinical trials are still about five years away. So play it safe until then, with the hopes that someday, doctors will be able to sketch you a replacement bone practically out of thin air. [University of Wollongong via MedicalXpress]